Fluorochemical textile resins have been used with great effect to impart or improve oil and water repellent characteristics of textiles. The common characteristic of these well-known fluorochemical textile resins is the presence of pendant perfluoroalkyl groups, which decrease the free surface energy of the fiber surface and accordingly, decrease the ability of liquids, polar or non-polar, to wet the fiber surface.
The mechanism of dry soiling, that is, soiling by particulate matter, is not influenced by free surface energy, but rather is a function of the surface characteristics of the finish, such as hardness, roughness and, notably, the antistatic properties thereof. For this reason, antistatic agents have been employed to reduce dry soiling in textile fabrics such as those which are intended for upholstery or carpeting. These antistatic agents are typically used at add-on levels of 3 to 10% by weight of fabric. One mechanism underlying the operation of the antistatic agents requires the presence of ambient moisture, which essentially acts as a conductor, thereby dissipating any static charge which would attract and hold particulate matter. The hydrophilic nature of these antistatic agents and the high add-on levels required increase wettability of the fabric by polar liquids, especially water. Thus, the properties of soil resistance and water repellency are antithetical. Those textile finishes which are highly water repellent, i.e. have AATCC spray ratings of 80-100, display very poor dry soil resistance while those textile finishes that display good dry soil resistance display poor water repellency (0-60 AATCC spray ratings).
It would be extremely useful to have a single finish which displays at the same time, the characteristics of high water and oil repellency together with high dry soil resistance.